The cross-coupling of a variety of terminal alkynes 1 with allenylphosphine oxides 2 catalyzed bya Pd(OAc)2-TDMPP system provided conjugated endo-enynes 3 solely, while the TCPC-catalyzedreaction of the same regents led to the exclusive formation of exo-isomers 4. The mechanisticrationale for these selective transformations was proposed. Synthetic usefulness of the preparedexo-enyne 4 was demonstrated in the synthesis of multisubstituted diarylbenzylphosphine oxides5 via the Pd-catalyzed [4+2]-benzannulation reaction.